using jointer as a planer

[Brian Runau]

any reason I can't use an 8" jointer as a planer as long as my stock is not too wide?

Thanks

[Heather Thompson]

A planer creates a flat surface relative to a flat surface, a jointer creates a flat surface and creates another flat surface off of the fence, it is possible to use a planer as a jointer if you use a sled. I do not see how you could use a jointer as a planer.

Heather

[Peter Aeschliman]

exactly. Said differently, there's no way to make two parallel sides on a jointer. You would end up with tapered boards if you tried to use your jointer as a planer.

[dirk martin]

If you are simply after a smooth face, then yes you can, however your board may not be the same thickness, end to end.

[David Winer]

exactly. Said differently, there's no way to make two parallel sides on a jointer. You would end up with tapered boards if you tried to use your jointer as a planer.
This is the convention, and the reason everyone knuckles down and buys a planer. But there is an exception: If your board has sufficient thickness relative to its face (such as a square cross-section) it's possible to surface a side then place that side firmly against the right-angle fence and create a ninety degree angled face. Then repeat the process until all four faces are jointed at right angles to each other.

Don't shoot. I'm just pointing out that it's feasible. For some purposes this produces a quick and not so dirty result.

[daniel lane]

This is the convention, and the reason everyone knuckles down and buys a planer. But there is an exception: If your board has sufficient thickness relative to its face (such as a square cross-section) it's possible to surface a side then place that side firmly against the right-angle fence and create a ninety degree angled face. Then repeat the process until all four faces are jointed at right angles to each other.

Don't shoot. I'm just pointing out that it's feasible. For some purposes this produces a quick and not so dirty result.

Ah, but you can have 4 faces perpendicular to each other but not with opposite sides parallel. Think truncated 4-sided pyramid.


daniel

[scott spencer]

Tough to do Brian. The planer makes the cut face parallel to the reference face....flat or not. A jointer flattens a face, but does nothing for parallelism. You can smooth a face with either tool.

[glenn bradley]

Ah, but you can have 4 faces perpendicular to each other but not with opposite sides parallel. Think truncated 4-sided pyramid.

Ya Mon. What he said. Jointers make things flat, planers make them parallel. I would do without a jointer before I would do without a planer. You can joint on a planer with a sled. I did for 18 months while I saved for a jointer.

[Jeff Monson]

Nice sled Glenn!!

[Michael Schwartz]

The problem with trying to use a jointer as a thickness planer would come that a jointer references off of the face of which it is cutting away the high spots at first and creating a flat, straight, board. A thickness planer references off of the opposite face creating a parallel surface, in reference to the opposing face.


The other problem would be that even if you did have a board of a perfect uniform thickness, to begin with and you wanted to use use the jointer to thickness it you would still have issues your tables would have to be perfectly coplanar with zero twist and your knives would have to be set perfectly, otherwise your boards would end up in the shape of a wedge/clapboard etc....

[David Winer]

Ah, but you can have 4 faces perpendicular to each other but not with opposite sides parallel. Think truncated 4-sided pyramid.


daniel
Wow, Daniel, you're right. And because of all that deep truncated pyramid thought I will probably not be able to sleep tonight.

BTW, I have used the jointer fence to create a decent rectangular cross section on a short board but it wouldn't pass some people's Quality Control standards.

[daniel lane]

BTW, I have used the jointer fence to create a decent rectangular cross section on a short board but it wouldn't pass some people's Quality Control standards.

Sorry for the lost sleep! :o

As for your efforts, I'm certain that they were more than adequate for the purposes! A lot of people did woodworking without planers for a long time, and while I'm not sure their efforts would pass a modern micrometer inspection, they look great.


daniel

[Brian Runau]

Thanks, I am enlightened.

[Mike Shields]

How about if the board you have is, say, a true 4/4.

And you want to make it 3/4. If you continue to run that 4/4 true
board across a jointer, you'll eventually get to 3/4.

You've just planed a board on a jointer.